Flow-reducing device particularly useful for trickle irrigation

ABSTRACT

A flow-reducing device is described particularly useful for trickle irrigation. The device includes a flow-retarding member formed with a plurality of holes extending therethrough from one face to the opposite face. The member is further formed on both faces with a plurality of recesses, each recess bridging a pair of holes. The recesses on one face overlap those on the opposite face, such that the pair of holes bridged by a recess on one face lead to separate recesses on the opposite face. The water is thus caused to flow through the holes and recesses in succession, passing back and forth from one to the other face of the member and finally exiting in a slow trickle.

United States Patent Drori Feb. 12, 1974 [54] FLOW'REDUCING DEVICEFOREIGN PATENTS OR APPLICATIONS PARTICULARLY USEFUL FOR TRICKLE l 513948 H1968 France 239/551 IRRIGATION 2,011,961 9/1971 Germany 239/553[76] Inventor: Mordeki Drori, 89 Zahal St., Kiron,

Israel Primary Examiner-Robert S. Ward, Jr. [22] Filed: Man 15 1973Attorney, Agent, or FirmBenjamin J. Barish [2i] Appl. No.: 341,713 [57]STRAC A flow-reducing device-is described particularly useful 30 F l t Pl orelgn App Ion nomy Data for trickle irrigationv The devlce Includes aflowx retarding member formed with a plurality of holes exay 23, 1972Israel 3951] tending therethrough from one face to the pp face. Themember is further formed on both faces [52] Cl 239/267 239/542 0 with aplurality of recesses, each recess bridging a Pair Int Cl Bosh U ofholes. The recesses on one face overlap those on the opposite face suchthat the pair of holes bridged [58] held of Search 239/542 322 7 by arecess on one face .lead to separate recesses on the opposite face. Thewater is thus caused to flow through the holes and recesses insuccession, passing [56] References cued back and forth from one to theother face of the mem- UNITED STATES PATENTS her and finally exiting ina slow trickle. 2,213,955 9/1940 Freitas 239/542 3,586,239 6/1971 Blass239/542 x 12 Chums, 19 D'awmg guns I ll 24 2s 2; 20 |2 2 2 l4 l 7W777Wlk 1 BACKGROUND OF THE INVENTION The present invention relates toflow-reducing devices, and particularly tosuch devices useful fortrickle irrigation.

Trickle irrigation is increasingly gaining wide-spread use as a meansfor supplying water, and sometimes fertilizer and other soil additives,to field crops and orchards.. In some known devices, the trickle flow ofthe water is effected by small openings, but these devices have thedisadvantage that they easily clog. In other devices, a long-circuitouspath, sometimes called a labyrinth or maze, is provided for the water sothat it eventually discharges in the form of a slow trickle. The knowndevices of this type, however, are generally large, expensive, and/ordifficult to clean and maintain because of the long circuitous path thatmust be provided.

BRIEF SUMMARY OF THE INVENTION An object of the present invention is toprovide a novel flow-reducing device, particularly for trickleirrigation, the type including a long circuitous path for the water,which device can be built of small size and low cost when compared tothe known trickle devices.

Briefly, the novel device includes a flow-retarding member disposedwithin a housing and formed with a large number of holes extendingcompletely through the member from one face to the opposite face, andhole-bridging means providing flow paths between the holes at both facesto direct the fluid entering through the inlet hole to flow through theholes in succession, passing back and forth from one to the oppositeface of the member, before exiting from the housing.

Conceivably, the hole-bridging means would be recesses formed in thehousing walls (or other members disposed within the housing) whichcontact the two faces of the flow-retarding member. Preferably, however,and in accordance with another feature of the invention, the holebridging means comprises a plurality of recesses formed on both faces ofthe flow-retarding member, each recess bridging a pair of holes, thepair of holes bridged on one face by one recess leading to separaterecesses on the opposite face. The walls in contact with both faces ofthe member thus direct the fluid to flow through these recesses whenpassing from one hole to the next.

Such a constructionproduces a very large flow path in a very smallspace. Moreover, the flow path produced has many sharp turns, walldiscontinuities, and alternations of narrow cross-sections,(the, holes)with large cross-sections (the recesses). The velocity of the fluid thuschanges frequently and abruptly, the fluid moving faster through theholes and slower through the recesses. The fluid is thus subjected, in arelatively small space, to considerable friction, eddying swirling, andturbulence, which thus reduces its pressure until it exits at a veryslow rate.

Another advantage of such a construction is that it can be produced involume at low cost.

The flow-retarding member may take many different forms, some of whichare described below. In general, it is relatively thin, having athickness which is a small fraction of its length.

According to a further feature of the invention, the flow retardingmember maybe in the form of an insert which is removably applied throughone end of the housing. Such an arrangement simplifies the manufacutreof the device, and particularly simplifies its maintenance and repair,since the insert may be conveniently removed, inspected, cleaned andreplaced in the field.

Further features and advantages of the invention will be apparent fromthe description below.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is described herein, byway of example only, with reference to the accompanying drawings,wherein:

FIG. 1 is a longitudinal sectional view of one form of trickleirrigation device constructed in accordance with the invention, FIGS. 1aand 1b illustrating the two faces of the flow-retarding member used inthe device;

FIG. 2 is a longitudinal sectional view of another trickle deviceconstructed in accordance with the invention, FIG. 2a illustrating amodification thereof;

FIG. 3 is a view, partly in transverse section, illustrating a furthertrickle device constructed in accordance with the invention, FIG. 3abeing an enlarged fragmentary view thereof, and FIG. 3b illustrating oneface of the flow-retarding member used therein;

FIG. 4 is a transverse sectional view of a further trickle deviceconstructed in accordance with the invention, FIG. 4a illustrating theflow-retarding member used therein, and FIG. 4b being a partialsectional view along lines BB of FIG. 4a;

FIG. 5 is a view, partly in transverse section, illustrating a stillfurther trickle device constructed in accordance with the invention,FIG. 5a being a sectional view along lines AA of FIG. 5, and FIG. 5billustrating the flow-retarding member used in the device of FIG. 5;

FIG. 6 is a longitudinal sectional view of a further trickle deviceconstructed in accordance with the invention, FIG. 6a being a sectionalview along lines A--A of FIG. 6, and 6b illustrating the flow-retardingmember used in the device of FIG. 6; and

FIG. 7 is an end elevational view illustrating a still further trickleirrigation device constructed in accordance with the invention, FIG. 7abeing a sectional view along lines AA of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The trickle irrigation deviceor nozzle illustrated in FIG. 1, la, lb of the drawings is embodied inan in-line coupling, for coupling two water supply pipes (not shown).The device comprises a housing, generally designated 2, including twosections 4,6 each formed with ribbed sleeve 8,10, for receiving therespective ends of the water supply pipes. The two sections 4,6 arejoined together by threads as shown at 10, and each includes an annularwall 12,14 of disc-shape. A radial opening 16 is formed in section 6,this opening leading into the space between the two walls 12,14, andserving as an inlet thereto for the water passing through the watersupply pipes.

A disc-shaped flow-retarding member 20 is disposed in the space betweenthe two walls 12,14 of the housing. Member 20 is formed with a largenumber of holes 22 extending therethrough from one face 24 (FIG. 1b)

to the opposite face 26 (FIG. 1a) thereof. Each face is also formed witha plurality of channels or recesses 28 each bridging a pair of holes 22.The recesses on one face (e.g., 24) overlap those on the other face(e.g., 26) such that the pair of holes bridged by a recess on one facelead to separate recesses on the opposite face.

.One hole 22' in member communicates with inlet opening 16 of thehousing via a recess 28, this hole being called the inlet hole; andanother hole 22" serves as the outlet hole of the device, this holeleading to the outside via recess 28 In the assembled device, both faces24, 26 of the flow-retarding member 20 are firmly pressed against theflat faces of housing walls 12,14 whereupon the recesses 20 provideflow-paths between the holes 22 at both faces of the member. The waterentering the inlet hole 22 is thus directed by the recesses to flowthrough the holes 22 successively to pass back and forth from one to theopposite face of the member, and then to exit through outlet hole 22"and its recess 28".

Many arrangements may be used for the holes 22 and recesses 28. In FIGS.1a and lb, the holes 22 are formed on concentric circles 30, as also arethe recesses 28, but the latter further include radially extendingrecesses 29 to bridge the holes of adjacent concentric circles.

It will thus be seen that the flow-retarding member 20, and the faces ofthe walls 12,14 in contact therewith, force the water to flow through avery long circuitous path back and forth from one face of the member tothe other until it exits through outlet opening 22". It will also beseen that this flow path has manysharp turns. Further, thecross-sectional area of this path frequently and abruptly changes,relatively small crosssectional areas (the holes 22) alternating withrelatively large cross-sectional areas (the recesses 28). This producesfrequent and abrupt changes in the velocity of the flowing water, andalso discontinuities in the wall bounding the flow path. All thesefactors increase the friction, eddying, swirling and turbulence of thewater as it moves through this path such that a very reduced flow ortrickle is produced at the outlet end.

Moreover, this slowtrickle is produced by the use of a relatively smalldevice which can be inexpensively manufactured, and by the use ofrelatively large holes which have less tendency to clog. As one example,trickle irrigation nozzles can be produced according to the designs ofFIGS. 1, la and 1b having a flow-rate as low as 2 liters per hour usingopening (22) as large as 1.5 mm, and even larger.

The flow-rate can be even further reduced or even larger openings can beused, by providing a plurality of flow-retarding members producing aseries path for the water from one member to the next.

Such a trickle device is illustrated in FIG. 2, wherein twoflow-retarding members, 120a, 120b are interposed between the flat walls112,114 of the nozzle housing 102. Each member 120a, l20b is of the sameconstruction as the flow-retarding member 20 of FIG. 1, except theoutlet hole (22", FIG. 1) of the member communicates, via an opening 130in a separator member 132, with the inlet hole of the secondflowretarding member 120b. Thus the water flowing 130 of separator 132,and then successively through the holes of the" second flow-retardingmember b, finally exiting through outlet 134.

The trickle device illustrated in FIG. 2a is the same as that of FIG. 2,except that one of the walls, 114, of the housing is provided with ashroud 136, which together with the other wall 112 of the housing,completely encloses the flow-retarding members 120a, 1201; and theseparator member 130.

FIGS. 3, 3a and 3b illustrate a trickle device having a large number offlow-retarding members, each being in the form of a fiat ring 220a,220b, etc. (FIG. 3a), each pair of rings being separated by a separatorring 230. Thus, each flow-retarding ring 220 (see FIG. 3b) includes theplurality of holes 222 and bridging recesses 228, but in this case thereis only one (or a few) circular arrays of such openings and recesses. Inaddition, as in the case of separator member in FIG. 2, each separatorring 230 in the embodiment of FIG. 3 includes an opening 232 (FIG. 3a)providing communication between the outlet hole of one ring 220 and theinlet hole of the next ring 220.

The water thus flows back and forth from one face to the opposite faceof each ring 220, and then through opening 232 of the separator 230, tothe next flowretarding ring, until it traverses all the rings, and exitsin the form of a slow trickle.

The flow-retarding member is illustrated in the above-described trickledevices as being in the shape of a relatively thin flat plate or dischaving a thickness which is a small fraction of both the length andwidth (i.e., the diameter, in the case of the illustrated annular discsor rings) of the member. The member however, may take other shapes.

FIGS. 4, 4a and 4b illustrate a trickle device wherein theflow-retarding member is in the form of a strip 320 (i.e., its thicknessis a small fraction of its length) which is helically wound within thehousing. In this case the housing includes two sleeves, namely an outersleeve 312 and an inner sleeve 314, the latter being formed with ahelically-winding, upstanding wall 330. The flow-retarding strip 320,e.g., of flexible plastic material, is formed with the through-goingholes 322,.and with the bridging recesses 328 on its opposite faces. Thestrip is wound onto the inner sleever 314 between and against thehelical wall 330, and then the outer sleeve 312 is placed thereover.

It will be seen that the water entering the 'device through inlet 316will flow back and forth from one to the opposite face of strip 320while it progresses helically along the length of the device until itexits from outlet 334.

FIGS. 5, 5a and 5b illustrate a still further variation. Here, theflow-retarding member (shown as 420'in FIG. 5b) is of flat flexiblematerial, such as plastic. It is formed with the through-going holes 422and the bridging recesses 428 on both faces, as described earlier. Inaddition, it is formed with a central aperture 424 which communicateswith the inlet hole 422. The holes and recesses are arranged spirallyaround the central aperture 424, the outlet hole 422" being formed in acorner (the upper right comer in FIG. 5b) of the member.

FIG. 5 illustrates the trickle device applied as a tap to a water supplypipe, rather than as an in-line coupling between a pair of water supplypipes as in the previously described embodiments. In this case, a holeis formed in the wall of the water supply pipe 430, and an inlet stem432 is inserted through the hole and through the center aperture 424 ofthe flow-retarding member 420. The latter is wrapped around the pipe 430and is retained in place by a sleeve 412, constituting a portion of thehousing. A further sleeve 413 is inserted through the open end of sleeve412, between the latter and the flow-retarding member 420, and the openend is closed by a collar 414 threaded onto sleeve 412. Sleeve 413 isconical, and collar 414 abuts against the end of it, forcing same topress tightly against the flow-retarding member 420.

It will be seen that the inlet to the trickle device of FIG. 5 isthrough stem 432, the water flowing through inlet hole 422 of themember, and then successively through the other holes 422, back andforth from one to the other side of the member, and finally exitsthrough outlet hole 422" and the housing outlet 434.

FIGS. 6, 6a, and 6b illustrate a trickle device'in which theflow-retarding member is in the form of an insert which can be readilyinserted and removed from the housing. The insert, identified as 520 andshown per se in FIG. 6b, is in the form of a strip of flat material,preferably plastic of rectangular section. The holes 522 and therecesses 528 are formed in zig-zag fashion beginning with the lower endand proceeding to the upper end. Thus, the inlet hole 522' is at a lower(right) corner of the strip, and the outlet hole 522" is at an upper(left) corner.

FIGS. 6 and 6a illustrate the flow-retarding member 520 of FIG. 6b usedin an in-line coupling between a pair of water supply pipes. Thecoupling includes a sleeve 512 adapted to receive a water supply pipe ateach end, and an outer sleeve 514 of rectangular section joined tosleeve 512 along one side thereof. Outer sleeve 514, and the portion ofsleeve 512 to which it is joined, together form an axially-extendingcompartment 518 closed at one end 519 and opened at its opposite end.The compartment is of similar rectangular section as the flow retardingmember 520, and the latter is disposed within the compartment with theinlet hole 522' of the member communicating with inlet opening 516 insleeve 512.

It will be seen that the water entering inlet opening 516 will travelthrough the holes and recesses of the flow-retarding member 520, backand forth from one face to the other, until it exits through outlet hole522 and housing outlet 534, as described earlier with respect to theother embodiments.

The embodiment of FIGS. 6, 6a and 612 has the further advantage that theflow-retarding member 520 can be easily inserted and removed through theopen end (left) of the compartment 518, for purposes of inspection,cleaning, and replacement in the field. Also, if a different flow-rateis desired, this can easily be accomplished by merely substituting theinsert designed for the desired flow rate.

FIGS. 7 and 7a illustrate another embodiment of the invention, whereinthe trickle device is in the form of a tap which may be clamped onto awater supply pipe to tap the water from an opening formed in a wall ofthe pipe.

In this case, the housing of the trickle device also includes spacedinner and outer axially-extending walls 612, 614 defining anaxially-extending compartment 618 therebetween for receiving theflow-retarding member 620. Here, however, the walls are curved to form acurved compartment and terminates in extensions 615 enabling the housingto be clamped onto the water supply pipe 630. Further, the housingcontains a stem 632 formed with a bore 634 to provide communication withthe flow-retarding member 620 within compartement 618. Theflow-retarding member 620 is preferably also of flat flexible plasticmaterial of rectangular section, for example as members 420 and 520 inthe embodiments of FIGS. 5 and 6. This member also includes thethrough-going holes and recesses on both faces to cause the water toflow through the holes successively and to pass from one face to theother, beginning with the inlet hole communicating with stem 632.

To facilitate clamping the housing, constituting by sleeves 612 andsleeve 614, onto the water supply pipe 630, the housing is made offlexible material preferably plastic. The flow-retarding member 620inserted within compartment 618 is tightly press-fitted into thecompartment. To remove this member, it is only necessary a to flex thetwo ends 615 of the housing which releases the insert and permits itsremoval. Thus, the compartment may be open at both ends since the insertis firmly retained therein.

Many other variations, modifications and applications of the illustratedembodiments will be apparent.

What is claimed is:

1. A flow-reducing device particularly for trickle irrigation,comprising, a housing, a flow-retarding member disposed therein, saidmember being formed with a large number of holes extending therethroughfrom one face to the opposite face thereof, said housing including aninlet communicating with one of said holes, constituting the inlet holeof the member, and holebridging means providing flow paths between theholes at both faces of said member to direct the fluid entering throughthe inlet hole to flow through said holes in succession, passing backand forth from the one to the opposite face of the member, and then toexit through an outlet hole in the member.

2. A device according to claim 1, wherein said holebridging meanscomprises a plurality of recesses formed on both faces of theflow-retarding member, each recess bridging a pair of the holes, thepair of holes bridged on one face by one recess leading to separaterecesses on the oppositeface, and walls in contact with both said facesof the flow-retarding member to direct the fluid to flow through saidrecesses.

3. A device according to claim 2, wherein said flowretarding member isrelatively thin having a thickness which is a small fraction of itslength.

4. A device according to claim 2, wherein there are a plurality of saidflow-retarding members, and a separator member between each pair, saidseparator member being formed with a hole-providing communicationbetween the outlet hole ofone of the respective pair of flow-retardingmembers and the inlet hole of the other flow-retarding member of thepair.

5. A device according to claim 4, wherein each of said flow-retardingand separator members is in the form of an annular disc.

6. A device according to claim 1, wherein said housing includes an innersleeve, and an outer sleeve, and said flow-retarding member is in theform of a strip helically wound around the inner sleeve and enclosed bythe outer sleeve.

7. A device according to claim 1, wherein said flowretarding member isin the form of a removable insert, and said housing defines acompartment for said insert,

said compartment being open at least at one end to permit removal andinsertion of the flow-retarding member insert.

8. A device according to claim 7, wherein said compartment is curved,and said flow-retarding member insert is of flat flexible materialflexed to assume the curvature of the compartment.

9. A device according to claim 7, for applying to a fluid supply pipehaving an opening in a wall thereof,

wherein said housing includes curved flexible inner and outer wallsdefining said compartment and clampable onto the supply pipe, and aninlet stem carried by said inner wall for passing through the pipe wallopening, the flow-retarding member insert being disposed in thecompartment between the outer and inner housing walls and beingremovable from the open end thereof, said inlet stem including apassageway communicating with the inlet opening of the flow-retardingmember insert.

10. A trickle device including an inlet and an outlet for application toa water supply pipe to provide a slow water trickle therefrom, saiddevice comprising: a housing having an outer wall and a spaced innerwall; mean carried by said inner wall for attaching the housing to awater supply pipe to extend laterally of and parallel to the axis of thewater supply pipe when applied thereto; said outer and inner wallsdefining an axially extending compartment of rectangular section andopen at at least one end; the inner wall of the compartment includingsaid inlet, the latter communicating with the water flowing through thewater supply pipe; and a flow-retarding insert in said compartment andremovable from said open end thereof, said insert being of rectangularsectionand formed with a circuitous path for the water to travel fromsaid inlet to the outlet thereof.

11. A device according to claim 10, wherein said inner and outer wallsare of flexible material enabling same to be clamped onto the watersupply pipe and firmly holding the insert in the compartment; andwherein said inlet is in the form a stem adapted to pass through anopening in the water supply pipe when the device is clamped thereto.

12. A device according to claim 10, wherein said flow-retarding insertincludes a member formed with a plurality of holes extendingtherethrough from one face to the opposite face thereof, said insertbeing further formed with a plurality of recesses on both faces thereof,each recess bridging a pair of the holes, the pair of holes bridged onone face by one recess leading to separate recesses on the oppositeface.

1. A flow-reducing device particularly for trickle irrigation,comprising, a housing, a flow-retarding member disposed therein, saidmember being formed with a large number of holes extending therethroughfrom one face to the opposite face thereof, said housing including aninlet communicaTing with one of said holes, constituting the inlet holeof the member, and hole-bridging means providing flow paths between theholes at both faces of said member to direct the fluid entering throughthe inlet hole to flow through said holes in succession, passing backand forth from the one to the opposite face of the member, and then toexit through an outlet hole in the member.
 2. A device according toclaim 1, wherein said hole-bridging means comprises a plurality ofrecesses formed on both faces of the flow-retarding member, each recessbridging a pair of the holes, the pair of holes bridged on one face byone recess leading to separate recesses on the opposite face, and wallsin contact with both said faces of the flow-retarding member to directthe fluid to flow through said recesses.
 3. A device according to claim2, wherein said flow-retarding member is relatively thin having athickness which is a small fraction of its length.
 4. A device accordingto claim 2, wherein there are a plurality of said flow-retardingmembers, and a separator member between each pair, said separator memberbeing formed with a hole providing communication between the outlet holeof one of the respective pair of flow-retarding members and the inlethole of the other flow-retarding member of the pair.
 5. A deviceaccording to claim 4, wherein each of said flow-retarding and separatormembers is in the form of an annular disc.
 6. A device according toclaim 1, wherein said housing includes an inner sleeve, and an outersleeve, and said flow-retarding member is in the form of a striphelically wound around the inner sleeve and enclosed by the outersleeve.
 7. A device according to claim 1, wherein said flow-retardingmember is in the form of a removable insert, and said housing defines acompartment for said insert, said compartment being open at least at oneend to permit removal and insertion of the flow-retarding member insert.8. A device according to claim 7, wherein said compartment is curved,and said flow-retarding member insert is of flat flexible materialflexed to assume the curvature of the compartment.
 9. A device accordingto claim 7, for applying to a fluid supply pipe having an opening in awall thereof, wherein said housing includes curved flexible inner andouter walls defining said compartment and clampable onto the supplypipe, and an inlet stem carried by said inner wall for passing throughthe pipe wall opening, the flow-retarding member insert being disposedin the compartment between the outer and inner housing walls and beingremovable from the open end thereof, said inlet stem including apassageway communicating with the inlet opening of the flow-retardingmember insert.
 10. A trickle device including an inlet and an outlet forapplication to a water supply pipe to provide a slow water trickletherefrom, said device comprising: a housing having an outer wall and aspaced inner wall; mean carried by said inner wall for attaching thehousing to a water supply pipe to extend laterally of and parallel tothe axis of the water supply pipe when applied thereto; said outer andinner walls defining an axially extending compartment of rectangularsection and open at at least one end; the inner wall of the compartmentincluding said inlet, the latter communicating with the water flowingthrough the water supply pipe; and a flow-retarding insert in saidcompartment and removable from said open end thereof, said insert beingof rectangular section and formed with a circuitous path for the waterto travel from said inlet to the outlet thereof.
 11. A device accordingto claim 10, wherein said inner and outer walls are of flexible materialenabling same to be clamped onto the water supply pipe and firmlyholding the insert in the compartment; and wherein said inlet is in theform a stem adapted to pass through an opening in the water supply pipewhen the device is clamped thereto.
 12. A device according to claim 10,wherein said flow-retarding insErt includes a member formed with aplurality of holes extending therethrough from one face to the oppositeface thereof, said insert being further formed with a plurality ofrecesses on both faces thereof, each recess bridging a pair of theholes, the pair of holes bridged on one face by one recess leading toseparate recesses on the opposite face.